1. #6,815,833TWN10 primes

    Bi-Twin · ⛏️ coinsforall.io

Block #471,895

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/2/2014, 9:27:42 PM · Difficulty 10.4376 · 6,343,939 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
637502dadab1a883ad5fb7b0dab297aac2117a3d61e2abd9771d03ccd8e38b28

Height

#471,895

Difficulty

10.437630

Transactions

1

Size

200 B

Version

2

Bits

0a700880

Nonce

391,390

Timestamp

4/2/2014, 9:27:42 PM

Confirmations

6,343,939

Merkle Root

f8b4ebac580ff7de29fd86cc1c651d1b26940f22784339cf688e4fa234a22960
Transactions (1)
1 in → 1 out9.1600 XPM109 B
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

8.851 × 10⁹⁷(98-digit number)
88512586271092757888…92353113774831028739
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
8.851 × 10⁹⁷(98-digit number)
88512586271092757888…92353113774831028739
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.770 × 10⁹⁸(99-digit number)
17702517254218551577…84706227549662057479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.540 × 10⁹⁸(99-digit number)
35405034508437103155…69412455099324114959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.081 × 10⁹⁸(99-digit number)
70810069016874206311…38824910198648229919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.416 × 10⁹⁹(100-digit number)
14162013803374841262…77649820397296459839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.832 × 10⁹⁹(100-digit number)
28324027606749682524…55299640794592919679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.664 × 10⁹⁹(100-digit number)
56648055213499365048…10599281589185839359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.132 × 10¹⁰⁰(101-digit number)
11329611042699873009…21198563178371678719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.265 × 10¹⁰⁰(101-digit number)
22659222085399746019…42397126356743357439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.531 × 10¹⁰⁰(101-digit number)
45318444170799492039…84794252713486714879
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,770,782 XPM·at block #6,815,833 · updates every 60s
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